Door closer



DOOR CLOSER Filed Nov. 10, 1937 2 Sheets-Sheet l "h IVENTOR ATTORNEY July 30, 1940. W. BAN NE BERG 2,209,553

DOOR CLOSER Filed Nov. 10, 1937 2 Sheets-Sheet 2 ig.6l a

1 22 I j z 39a INVENTOR sYw /n/ ATTORNEY til Patented July 30, 1940 UNITED STATES DOOR CLOSER Application November 10, 1937, Serial No. 173,825 In Germany November 24, 1936 5 Ciaims.

This invention relates to door closers, and more especially to door closers of a type having checking mechanism to slow down the door closing movement.

The form of my invention shown in Figs. 1, 2 and 3 of the drawings to be described below, corresponds to the structure shown in my application for patent filed in Germany on November 24, 1936, designated by the German Patent Oflice as Y'720 III/68d. That portion of the invention shown in Figs. 4, 5 and 6 discloses a mechanical adaptation oi the structure of Figs. 1, 2 and 3.

Referring now to the drawings, Fig. 1 illustrates diagrammatically one form of my invention, while Fig. 2 is an end view of the casing of the door closer of Fig. 1, and Fig. 3 is a side view showing the casing of Fig. 1. Fig. 4 is a section through a mechanical embodiment of my invention, while Fig. 5 is a view of an end plate used in Fig. 4. Fig. 6 is a further modification of the invention.

Referring now more particularly to Figs. 1, 2 and 3, I shall now present a translation of the German application describing the invention, as follows:

The subject of this invention is a device provided with one or several springs to automatically open or close doors, such as door closers, or similar devices.

The devices which heretofore have been used for this purpose were generally provided with coiled springs, such as helical springs or torsion springs made from round or fiat wire. To obtain a spring tension that is sufficient for an automatic opening and closing action of doors, relatively strong springs with a great number of coils which take up considerable volume are required.

For a long while efiorts have been made to reduce the size of existing door closers without, however, reducing their efiiciency, in order to make better appearing door closers; to save raw material and to enable the mortising of door closers into doors. So far, these efforts have been in vain, because it is impossible to use smaller springs of the above-mentioned kind and springs that take up less room without reducing the tension.

This particular inventionoffers the possibility of considerably reducing the size of door closers, door openers or similar apparatus without reducing their efiiciency. The essential feature of the invention is that instead of wound and coiled springs, rod-formed torsion springs are used which, fixed at one end, by being wound up in one direction accumulate tension and then by unwinding movement in a reverse direction are relieved oftension, without changing the theoretical axis during the accumulation or relieving of the tension.

The torsion rod spring or rotation rod spring is utilized by fixing the torsion spring rod at one end, while the other end is rotated through the opening movement of the door as by means of a lever system, the opening action bringing about a rotation of the free end of the torsion spring. When the door is first opened and then released, the tensioned spring is released for action, and the door is closed automatically by the reverse movement Which operates the lever system. Naturally, oil-pressure brakes, air-pressure brakes, and friction-brakes that can be regulated may be used to check the door closing movement. If an oil-pressure brake is used, the rod-formed torsion spring can be arranged in a parallel direction to the movement of the piston, in which case the size of the door closer can be very much reduced.

The drawings show one example of how the invention works and represents an oil-braking door closer in its long-sectional view.,

The spring which is rotated while the door is opened and which brings about the closing of the door is, according to-this invention, a'torsion spring rod 1. The spring rod l is fixed at one end 2 and is arranged, at its other end 3, for pivoting about its theoretical axis. To obtain a rotation of the spring i around its theoretical axis and for rotating the spring in one or the other direction, I employ gears t and l, which are only schematically indicated in the drawings. This gearing is arranged for operation by the crank shaft i, incidental to its operation of connecting rod 5 and piston 8.

As shown in the drawings and just indicated, the crank shaft i and the connecting rod 5, influence the piston 8 which cooperates in the usual way with a regulating valve 9 and operates as a brake during the automatic closing of the door by the release ofthe spring I. The torsion rod is arranged parallel relatively to the movement of the piston and, for this reason, the various parts of the door closer can be housed in a particularly small shell H3. Of course, the door closer can be designed in a difierent way and can be provided with oil-pressure brakes, air-pressure brakes, or friction-brakes.

The rod-formed torsion spring I is considered best in a circular transverse-section and is made from a special heat-treated spring steel which is alloyed in a way that a greatnumber of load cycles is possible within the turning possibilities, without exceeding the elastic limit and without reaching the breaking point through fatigue. Naturally, the torsion spring does not necessarily have to be in a round form, but can be made in other forms, such as'cornered or flat profiles.

Referring now to Fig. 4, I show a door closer having a casing 20, a portion of which is formed as a cylinder 2| for housing a piston 22. This piston is connected through means of a pin 23 and connecting link 24 to the crank shaft 25 of the door closer. The shaft 25 is rotated by a door closer arm 26 of usual construction through the intermediary of the standard type of pawl 21 and ratchet 28 used on door closers. The construction just set forth is of the regular standard type, such as shown, for instance, in the patent to Potter, No. 1,926,558, assigned to The Yale 8a Towne Manufacturing Company, the owner of this application.

The rotation of the crank shaft 25 will cause rotation of a gear 29 which is keyed at 30 to the crank shaft 25. The gear 29 will in turn rotate a further gear 3| which is keyed at 32 to a torsion rod 33. The torsion rod 33 is in turn rotatably mounted at 34 in the end surface defining one end of the casing 25, and is secured against rotation at its other end 35 in a plate 36 fixed through lugs 3'! to the other end of the casing. A threaded cap 38 of standard construction covers the end of the casing and completes the cylinder portion 2| of the casing. Valve mechanism 39 of a type well known in the art is of course provided and need not be further described here, it being understood that the function of the valve mechanism 39 is to control the flow of oil under the influence of the piston 22 as the piston is moved under the action of torsion rod 33.

An especially novel feature of the modification of Fig. 4 is the mounting of the torsion rod 33 so that the piston may slide relatively thereto. For this purpose, the piston is bored out as at 4|] preferably for a sleeve 4|, although it should be understood that the sleeve 4| may be eliminated and the piston slide directly relatively to the torsion rod 33.

Through a packing 42 held in position by a suitable threaded packing nut 43, the flow of fluid between the sleeve 4| and the piston 22 is adequately controlled. The sleeve 4| is of course fixed against rotation through securing means holding it against rotation and endwise separation from the plate 36. It is thought that the action of the modification of Fig. 4 will now be quite clear, but it will probably be helpful to describe that action here.

It will be understood that rotation of the door closer arm 26 incidental to the opening movement of the door to which my closer is applied, will rotate crank shaft 25 which in turn will cause rotation of the gears 29 and 3|, whereby to twist the torsion rod 33. At the same time, the piston 22 will be moved from its extreme end position of Fig. 4 to a position nearer the left end of the cylinder portion 2| of the door closer. When the door is released, the torsion rod 33 will come into play and will gradually close the door under. control of the piston 22 which slows down the action of the closer by forcing oil through the valve mechanism 39 at a speed determined by the setting of the valve mechanism.

The modification of Fig. 6 is similar in operation to the modification of Fig. 4, except that two torsion rods are used, one being designated by reference numeral 45, while the other is designated by reference numeral 46. The end 41 of the rod 46 is secured against rotation, the other end 48 being secured for rotation on the bottom of the casing 49 of the door closer. The first torsion rod 45 is adapted for rotation at both ends 50 and 5|. The rod 45 is rotated through its gear 52 by a gear 53 carried by the central crank shaft 25a of the closer, and through its gear 54 meshing with gear 55 of the rod 46, it rotates the rod 46.

It will be understood that in the modification of Fig. 6, the rotation of the crank shaft 25a will act to wind up the torsion rods 45 and 46 in the same manner as is wound up the single torsion rod 33 in the modification of Fig. 4. When the door is released, the torsion rods 45 and 46 act as does the torsion rod 33 to force the closing of the door under the influence of the piston 22a as controlled by the valve mechanism 39a.

I new claim:

1. In a door closer of the class described, a main rotating shaft, a torsion rod rotated by said shaft, a checking piston connected to said shaft, a cylinder in which said piston slides, a portion of said torsion rod extending longitudinally of said cylinder, said piston having a bore for the passage of said torsion rod for allowing sliding movement of said piston relatively to said torsion rod.

2. In a door closer of the class described, a main rotating shaft, a torsion rod rotated by said shaft, a checking piston connected to said shaft, a cylinder in which said piston slides, a portion of said torsion rod extending longitudinally of said cylinder, a stationary longitudinal sleeve in said cylinder surrounding said torsion rod, and a longitudinal bore in said piston for the passage of said sleeve whereby said piston may slide in said cylinder and about said sleeve.

3. In a door closer of the class described, a casing, a main rotating shaft in said casing, an arm secured to said shaft at one end and at its other end to one end of a second arm, means securing the other end of said second arm to the door frame, whereby opening of the door rotates said main shaft, a series of spring torsion rods having their ends in geared relation as in a gear train, the first of said torsion rods being adapted for rotation at one end by said main shaft incidental to the opening of the door, the other end of said rod transmitting torsion to the next rod through said geared connection, the last of said series of torsion rods being secured at one end against rotation whereby the said rotation of said rods effects a twisting thereof to store energy therein.

4. In a door closer of the class described, a casing, a main rotating shaft in said casing, a series of spring torsion rods having their ends in geared relation as in a gear train, the first of said torsion rods being adapted for rotation at one end by said main shaft incidental to the openingof the ouor, the other end of said rod transmitting torsion to the next rod through said geared connection, the last of said series of torsion rods being secured at one end against rotation whereby the said rotation of said rods effects a twisting thereof to store energy therein.

5. In a door closer of the class described, a casing, a main rotating shaft in said casing, a series of spring torsion rods having their ends in geared relation as in a gear train, the first of said torsion rods being adapted for rotation at one end by said main shaft incidental to the opening of the door, and adapted through said geared connection to transmit torsion to the next of said torsion rods, and so on, the last of said series of torsion rods being secured at one end against rotation whereby the said rotation of said rods efiects a twisting thereof to store energy therein.

WILHELM BANNENBERG. 

